Huntington’s disease overview
Huntington’s disease is an inherited disorder in which there is gradual atrophy of the brain striatum.1,2 Over many years, a person with Huntington’s disease may experience uncontrolled movements, behavioral disturbances and mental deterioration.2 Ultimately, people with Huntington’s disease become completely dependent on a caregiver.3 This places a huge burden on the caregiver, who is usually a family member.
Huntington’s disease is an autosomal dominant disorder, affecting both genders equally.4 If one parent has the disease, each child has a 50% chance of inheriting the defective Huntington’s disease gene.2 Everyone who has this defective gene will eventually develop symptoms of the disease.3
The signs and symptoms of Huntington’s disease most often appear in middle age, though this varies from person to person. As the disease progresses, the patient may show changes in behavior and personality, including depression, irritability and anxiety. Problems with cognition and memory also can occur.2,5
Chorea is the most visible symptom of HD and occurs in approximately 90% of patients at some point in their illness.6,7 Chorea consists of jerky, involuntary movements of the upper and lower extremities, face or body. The word chorea comes from the Greek word for ‘dance’, since people with chorea often writhe, twist and turn in a characteristic dance-like motion.2,10
It is estimated that for every 100,000 people worldwide, 5–10 will have Huntington’s disease.8
Huntington’s disease can affect men and women of all ethnic backgrounds.3 The disease occurs throughout the world, however, there are geographic clusters where it is unusually common.9
There are no accurate estimates of the number of new cases each year.9
Seeking diagnosis and care
A doctor should be consulted at the first onset of symptoms, such as changes in movements, emotional state or mental ability. While a family doctor may be able to diagnose Huntington’s disease, most people will see a neurologist to confirm the diagnosis and to get help in managing their various symptoms. Huntington’s disease is typically diagnosed after a thorough neurological examination, including brain imaging or genetic testing, and a review of family history.
There is also a genetic test for Huntington’s disease, which can be used to confirm a diagnosis, and also identify future risk in people who have Huntington’s disease in their family.2 It is recommended that the genetic test be accompanied by counselling, since a positive diagnosis can be emotionally devastating.2
There is no cure for the disease, and the average life expectancy following diagnosis is about 10–30 years.2
It is essential that people with Huntington’s disease seek comprehensive care from trained professionals.
Seeking diagnosis and care
1. Gil, Joana M. (University of Victoria, Canada); Rego, Ana Cristina (University of Coimbra, Portugal). Mechanisms of Neurodegeneration in Huntington’s disease. European Journal of Neuroscience (EJN), 2008.
2. MayoClinic.com. Huntington’s disease. May 2011. www.mayoclinic.com/print/huntingtonsdisease/DS00401/DSECTION=all&METHOD=print. Accessed 10/05/11.
3. World Health Organization (WHO). Genes and human disease: Huntington’s disease. www.who.int/genomics/public/geneticdiseases/en/index2.html#HD. Accessed 09/28/11.
4. Gusella, James F.; MacDonalid, Marcy E. Genetics and Molecular Biology of Huntington’s Disease. Clinical Disorders Chapter 34, 2004.
5. National Institute of Neurological Disorders and Stroke Huntington's Disease Information Page: ninds.nih.gov/disorders/huntington/huntington.htm. Accessed 09/28/11.
6. Kirkwood, Sandra Close, PhD; Su, Jessica L., MS; Conneally, P. Michael, PhD; Foroud, Tatiana, PhD. Progression of Symptoms in the early and Middle Stages of Huntington Disease. Archives of Neurology, 2001.
7. Haddad, Monica Santoro,/Cummings, Jeffery L.. Neuropsychaitry of the Basal Ganglia, “Huntington’s Disease”. December 1997, Volume 20, number 4.
8. Marshall, Frederick J. Clinical Features and Treatments of Huntington’s Disease. Clinical Disorders Chapter 35, 2004.
9. Revilla, Fredy J. Huntington disease. Medscape Reference 2011. emedicine.medscape.com/article/1150165-overview#showall. Accessed 09/28/11.
10. Huntington’s Disease Society of America. Glossary.
http://www.movementdisorders.org/MDS/About/Movement-Disorder-Overviews/Chorea--Huntingtons-Disease.htm. Accessed 10/05/11.